Field of the Invention
The present invention relates to a photoelectric conversion apparatus and a camera equipped with it.
Description of the Related Art
Japanese Patent Laid-Open No. 2009-252782 has described a solid-state image sensor having a structure which suppresses the influence of a dark current generated in an element isolation insulation layer. The solid-state image sensor includes a photoelectric conversion unit formed by a p-type well region and an n-type region, the element isolation insulation layer, the first p-type element isolation layer arranged between the element isolation insulation layer and the n-type region, and the second p-type element isolation layer arranged under the first p-type element isolation layer. The first p-type element isolation layer and the second p-type element isolation layer are provided so as to surround the photoelectric conversion unit.
A defect exists at the interface between an element isolation and a semiconductor substrate. If a dark current generated in the defect flows into the photoelectric conversion unit, this becomes noise. In the solid-state image sensor, this noise can be a cause of decreasing the S/N ratio of an image or generating a white spot in the image. The structure described in Japanese Patent Laid-Open No. 2009-252782 is advantageous in reducing noise as described above. However, a further reduction in noise is required.